Figure 2

Effector T cells (TE) can be derived from naïve (TN), central memory (TCM), and effector memory (TEM) subsets and express a CD62L-, CCR7-, granzyme Bhi, and perforinhi phenotype. Despite the similar phenotype at the time of adoptive transfer, T cells derived from TEM precursors die rapidly after cell transfer and do not establish persistent T cell memory. T cells derived from TCM precursors survive long term in vivo and revert to both CD62L+ and CD62L- memory cells. A subset of the transferred cells that reexpress CD62L and CCR-7 reside in lymph nodes, downregulate expression of granzyme B and perforin and are capable of responding to antigen challenge. The fate of TE derived from naïve precursors in vitro has not yet been definitively established in a large animal model.